package com.bv.hr.common.utils;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;

/**
 * @author CYT7
 * @version 1.0
 * @time 12月 20,2021
 * @describe 密码加密
 */
public class PasswordEncoder {
    private final static String[] HEX_DIGITS = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
            "e", "f" };
    private final static String MD5 = "MD5";
    private final Object salt;
    private final String algorithm;

    public PasswordEncoder(Object salt) {
        this(salt, MD5);
    }
    public PasswordEncoder(Object salt, String algorithm) {
        this.salt = salt;
        this.algorithm = algorithm;
    }

    /**
     * 密码加密
     * @param rawPass 原始密码
     * @return 加密后的密码
     */
    public String encode(String rawPass) {
        String result = null;
        try {
            MessageDigest md = MessageDigest.getInstance(algorithm);
            //加密后的字符串
            result = byteArrayToHexString(md.digest(mergePasswordAndSalt(rawPass).getBytes(StandardCharsets.UTF_8)));
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return result;
    }
    /**
     * 密码匹配验证
     * @param encPass 密文
     * @param rawPass 明文
     */
    public boolean passwordMatching(String encPass, String rawPass) {
        String pass1 = "" + encPass;
        String pass2 = encode(rawPass);

        return !pass1.equals(pass2);
    }
    private String mergePasswordAndSalt(String password) {
        if (password == null) {
            password = "";
        }

        if ((salt == null) || "".equals(salt)) {
            return password;
        } else {
            return password + "{" + salt.toString() + "}";
        }
    }
    /**
     * 转换字节数组为16进制字串
     * @param b 字节数组
     * @return 16进制字串
     */
    private String byteArrayToHexString(byte[] b) {
        StringBuilder result = new StringBuilder();
        for (byte value : b) {
            result.append(byteToHexString(value));
        }
        return result.toString();
    }
    /**将字节转换为16进制*/
    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n = 256 + n;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return HEX_DIGITS[d1] + HEX_DIGITS[d2];
    }
}
